A conventional storage array provides disk storage and multiple storage processors allowing access by one or more external host computers to the disk storage. The system can produce a large number of hardware and software errors. To test error handling and response in the conventional storage array an injection tool for injecting an error on the send path of an I/O request is used. The injection tool receives from an individual testing the storage array a Logical Block Address (LBA) or LBA range of addresses and an error code to be created upon access to the LBA or LBA range. The individual testing the storage array also runs a test sequence that attempts to access blocks in the LBA on the storage array. The storage array recognizing the LBA in the I/O request catches the I/O request and returns the error code back up the software stack of the I/O request. The operating software in storage array above the point where the I/O request is caught then exercises error correction routines in response to the returned error code.